Java CLI : Cant parse arguments

Question

我正在尝试将命令行参数解析为

Options options = new Options();
        options.addOption("c", "count", false, "number of message to be generated");
        options.addOption("s", "size", false, "size of each messages in bytes");
        options.addOption("t", "threads", false, "number of threads");
        options.addOption("r", "is random", false, "is random");
        CommandLine cli = new DefaultParser().parse(options, args);

        int count = Integer.parseInt(cli.getOptionValue("c", "20000000"));
//        int count = Integer.parseInt(cli.getOptionValue("c", "100"));
        int recordSize = Integer.parseInt(cli.getOptionValue("s", "512"));
        int threads = Integer.parseInt(cli.getOptionValue("t","4"));
        boolean isRandom = Boolean.valueOf(cli.getOptionValue("r", "true"));
        System.out.println(" threads "+threads);
        System.out.println(" count "+count);

我在 Eclipse 中运行它

t 6 c 7

但我总是得到

threads 4
count 20000000

我错过了什么？

Answer 1

当选项带有参数时，您应该对 addOption 方法使用 true。来自 Javadoc:

• @param hasArg flag signally if an argument is required after this option

    options.addOption("c", "count", true, "number of message to be generated");
    options.addOption("s", "size", true, "size of each messages in bytes");
    options.addOption("t", "threads", true, "number of threads");
    options.addOption("r", "is random", false, "is random");

是的，对于短选项规范(例如 -t 4)需要一个前导 -，对于短选项规范需要一个前导 --长选项规范(例如 --threads 4)。